The infrared excess of G29-38 - A brown dwarf or dust?
نویسندگان
چکیده
منابع مشابه
Keck Speckle Imaging of the White Dwarf G29-38: No Brown Dwarf Companion Detected
The white dwarf Giclas 29-38 has attracted much attention due to its large infrared excess and the suggestion that excess might be due to a companion brown dwarf. We observed this object using speckle interferometry at the Keck telescope, obtaining diffraction-limited resolution (55 milliarcseconds) at K band, and found it unresolved. Assuming the entire K band excess is due to a single point-l...
متن کاملDiscovery of Photospheric Calcium Line-Strength Variations in the Dazd White Dwarf G29-38
Metals in the photospheres of white dwarfs with TeA between 12,000 and 25,000 K should gravitationally settle out of these atmospheres in 1Y2 weeks. Temporal variations in the line strengths of these metals could provide a direct measurement of episodic metal accretion. Using archival VLTand Keck spectroscopy, we find evidence that the DAZd white dwarf G29-38 shows significant changes in its Ca...
متن کاملThe Dust cloud around the White Dwarf G 29 - 38
We present new observations of the white dwarf G 29-38 with the camera (4.5 and 8 μm), photometer (24 μm), and spectrograph (5.5–14 μm) of the Spitzer Space Telescope. This star has an exceptionally large infrared excess amounting to 3% of the bolometric luminosity. The spectral energy distribution has a continuum peak around 4.5 μm and a 9–11 μm emission feature 1.25 times brighter than the co...
متن کاملThe Limiting Effects of Dust in Brown Dwarf Model
We present opacity sampling model atmospheres, synthetic spectra and colors for brown dwarfs and very low mass stars in two limiting case of dust grain formation: 1) inefficient gravitational settling i.e. the dust is distributed according to the chemical equilibrium predictions, 2) efficient gravitational settling i.e. the dust forms and depletes refractory elements from the gas, but their opa...
متن کاملThe Near-infrared Spectrum of the Brown Dwarf Gliese 229b
A medium resolution 1.0− 2.5 μm spectrum of the brown dwarf, Gliese 229B has been obtained using CGS4 on UKIRT. In addition to the broad spectral structure seen in earlier low resolution observations, the new spectrum reveals a large number of absorption lines, many of which can be identified with water vapor. Water and methane are both shown to be strong absorbers in the near-infrared spectrum...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 1990
ISSN: 0004-637X,1538-4357
DOI: 10.1086/168907